1. Field of the Invention
The present invention relates to a disk device and a firmware determination method. In particular, the invention relates to a disk device using a disk to rewrite firmware that is stored in a nonvolatile memory for performing basic control of the disk device and to a determination method for the firmware.
2. Description of the Background Art
A disk device includes firmware that is provided in advance for basic control of hardware. The firmware is software that is stored in a flash memory (nonvolatile memory) as a program executed immediately after the system is powered and that is embedded in advance in the disk device. The firmware functions as a part of the hardware. When it is necessary to change any function of the device or correct any malfunction, the firmware is rewritten to be upgraded (updated).
The firmware includes an HW code (hardware code) specifying the attribute of the target hardware (hardware controlled by the firmware). There are disk devices of many models, and the HW code is different depending on the model. In the case where a disk having firmware stored thereon for rewriting (firmware of a new version) is used to upgrade the firmware in the disk device, the disk is inserted into the disk device, the HW code of the firmware in the device is compared with the HW code of the firmware on the disk. If the HW codes are identical to each other (if the firmware in the device and the firmware on the disk are of the same model), the firmware in the device is rewritten.
Japanese Patent Laying-Open No. 2000-207180 discloses an information processing device having a memory card storing a determination routine for determining in what case a program in the device should be rewritten. The determination routine is executed by the device on the memory card to determine whether or not upgrade is necessary. In this way, the information processing device can individually and appropriately address various environmental changes occurring after product shipment.
It is supposed here that a disk device of model A and a disk device of model B have respective functions similar to each other (these disk devices are of models that are functionally compatible with each other, hereinafter referred to as “compatible models”) while respective flash memories are different in capacity for example and accordingly respective firmwares stored respectively in the flash memories are different in HW code. In this case, even if it is tried to use a disk storing new-version firmware compatible with the disk device of model B for the purpose of upgrading the firmware of the disk device of model A, this upgrade cannot be achieved due to the HW codes different from each other. Specifically, the upgrade cannot be achieved since it is determined that the firmware of the disk is incompatible with the disk device because the HW code of the disk's firmware differs from that of the disk device. Thus, there arises a necessity to improve compatibility of the firmware, so that respective firmwares of disk devices that are of different models while they are compatible with each other can be upgraded using firmware of any of the compatible models.